This invention broadly relates to deep rolling fillets of engine crankshafts or other annular areas of metallic work pieces subject to high stress loads. More particularly, this invention relates to a new tool mechanism for deep rolling machines, wherein the tool mechanism includes a new and unique cage and cage retainer design for holding the work rollers.
The state-of-the-art is indicated by the following cited references: Gottschalk, U.S. Pat. Nos. 5,495,738; Gottschalk, et al. 5,445,003; Bone, 5,493,761; Winkens, 5,138,859; Berstein, 4,561,276; and Ostertag, 4,947,668. The disclosures of Lonero, et al. U.S. Pat. Nos. 5,699,692 and Lonero, et al. 5,806,184 are hereby incorporated herein by reference.
Various machines and methods have been employed to strengthen and finish metal work pieces such as crankshafts and camshafts for internal combustion engines. In many modern automobiles, engines have been downsized for installation into small vehicles. Accordingly, with downsizing of automotive vehicles and their components for reducing weight and improving fuel efficiency, smaller engines and crankshafts are often used. To improve the fatigue strength and durability of these crankshafts, deep rolling of fillets and other circular joint areas is increasingly important. The fatigue strength and durability of crank pins and main bearing journals can be significantly increased by deep rolling compressive stresses into the middle of the annular fillets between the pin journals and adjacent counter weights or balancing webs.
In previously designed tool mechanisms for deep rolling machines the cage members which hold the working rollers during the deep rolling operation are subjected to wear and tear; and, also these cage members are subjected to damage or breaking during operation of the tool mechanism. Also, previously designed tool mechanisms for deep rolling possess tab members (on the cage retainers) which often were damaged, cracked or broken during usage of the tool mechanism.
Accordingly, one object of the present invention is to provide a novel design for a tool mechanism used in deep rolling operations wherein the cage structure for the tool mechanism is of a new and unique design.
Another object of the present invention is to provide a new and improved tool mechanism for deep rolling operations wherein the cage design for the tool includes the novel use of a supporting pin structure to greatly improve the strength and durability of the cage design and the cage retainer members.
Still another object of the invention is to provide a newly designed tool mechanism for deep rolling operations which has an improved and unique cage design for holding the work rollers, and which also is designed such that the tool mechanism can be cleaned in conventional ultrasonic cleaning systems without disassembly.
Other objects features and advantages of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings (wherein like numerals indicate like elements).